T1rho mapping of entire femoral cartilage using depth- and angle-dependent analysis

Taiki Nozaki, Yasuhito Kaneko, Hon J. Yu, Kayleigh Kaneshiro, Ran Schwarzkopf, Takeshi Hara, Hiroshi Yoshioka

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Objectives: To create and evaluate normalized T1rho profiles of the entire femoral cartilage in healthy subjects with three-dimensional (3D) angle- and depth-dependent analysis. Methods: T1rho images of the knee from 20 healthy volunteers were acquired on a 3.0-T unit. Cartilage segmentation of the entire femur was performed slice-by-slice by a board-certified radiologist. The T1rho depth/angle-dependent profile was investigated by partitioning cartilage into superficial and deep layers, and angular segmentation in increments of 4° over the length of segmented cartilage. Average T1rho values were calculated with normalized T1rho profiles. Surface maps and 3D graphs were created. Results: T1rho profiles have regional and depth variations, with no significant magic angle effect. Average T1rho values in the superficial layer of the femoral cartilage were higher than those in the deep layer in most locations (p < 0.05). T1rho values in the deep layer of the weight-bearing portions of the medial and lateral condyles were lower than those of the corresponding non-weight-bearing portions (p < 0.05). Surface maps and 3D graphs demonstrated that cartilage T1rho values were not homogeneous over the entire femur. Conclusions: Normalized T1rho profiles from the entire femoral cartilage will be useful for diagnosing local or early T1rho abnormalities and osteoarthritis in clinical applications. Key Points: • T1rho profiles are not homogeneous over the entire femur. • There is angle- and depth-dependent variation in T1rho profiles. • There is no influence of magic angle effect on T1rho profiles. • Maps/graphs might be useful if several difficulties are solved.

Original languageEnglish
Pages (from-to)1952-1962
Number of pages11
JournalEuropean radiology
Issue number6
Publication statusPublished - 2016 Jun 1
Externally publishedYes


  • 3D graph
  • Angle and depth analysis
  • Entire femoral cartilage
  • Surface map
  • T1rho

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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